Evening star. [volume] (Washington, D.C.) 1854-1972, 1887-04-16
PHOTOGRAPHING THE SKY.
An Astronomical Work i'm which the
Naval Observatory II Invited 60 Take
Part.

Lieut.. Winterhalter, one Of the naval officers at
tached 10 the Naval Observatory, has as stated
IN The STAR gone TO Paris TO take part in the
ference which will meet there to-day for the pur-
pose OF forming plan OF cooperation I'm photo-
graphing the whole sky. This conference has
oeen called by Admiral Mouchez, director OF the
Parls Observatory. Capt. Brown OF the Naval
Observatory, when asked by a STAR reporter
ABOUT the project said that this con-
ference would discuss the matter and endeayor
10 devise plan that would secure uniformity IL
was proposed, OF course TO have at the different
places where photographs are 20 be made instru-
ments exactly alike and uniform in power There
are are many little points TO be considered,
the size and character OF the plates
20 be used, the length OF exposure
ior stars OF greater or less magnitude, sc IL is
nopea ~ nave The work carried on with such uni
Iorhiily ihat Tue results win be homogeneous and
comparable The proposition is 10 enlist ten or
tweiSe oDServaiories I'm the OBSERVATION-DISCLOSURES
ZONES ,,, 80 located that their combined range
viii take In the whole sky. The Naval observa-
VoIy at Mashington. for instance, will have a GER
tam portion oil the sky 20 photograph, and the sky
VIII pe apporuoned out, 80 that the field in which
one observatory works win lap over the fields OF
Others. thus providing margin which viii aid In
securing accuracy. suggestion has been made
which II adopted would require II, 90 plates. Il
10 estimated that with an average OF
tories o Plates ess, per year from eleven observe,
square, IL would take ten years TO complete
the whole work. Capt Brown said that while Lieut..
Wlnterhalter takes part in the conference, he is
not authorized TO bind this government TO take
part In the work He will report the results OF the
conference and IL IL Is decided TO take part In the
work, Congress viii have 10 provide the means for
obtaining the necessary Instruments.
Wlthn recent years the value OF photography
as an aid TO the astronomer has been demons rated
10 many marked ways. Professor Hall has at the
Naval Observatory. a photograph made by Prof
fickerlng OF section OF sky including the Peiades
ABOUT one OF these stars In the group appears I'm
the photograph little murky cloud, which, when
the photograph was first made, was attributed 20
deiects OF the glass. Photographs made by the
Henrys also showed q similar cloud, and the pho
tographs established the fact that the star was
surrounded by nebula never before discovered
Professor Hall said 10 STAR reporter that he had
observed simmer OF light about the star through
the great equatorial instrument, but had not been
able 10 determine its character.
Telescopes for Photographic work have been
arranged so as TO provide for long exposure A
double telescope is used, and the observer or
operator who looks through one regulates the in
struments so that the Star is eonsl antly kept In
The same position In the field. The value OF pho
geography In star charting has already been demon
strated. The distances from star TO star can be
easily determined on the photographs with meas
ur1ng machines. The work OF star charting with
out such aid is very tedious. Many ob,erS atious
OF the same star have to be made.